Inhibition of growth
Looking a bit critically 15-, 20-kilogram carp caught in the last few years, it's easy to see, that these fish stopped growing, they only keep their body weight unchanged. And yet, at least I believe it, their possibilities are not exhausted yet. These carps could well be even bigger, however, development has stopped. Cuts after being caught with a fishing rod and being constantly disturbed, that the fish are running out of vitality, to keep growing. W Lac Cassien, due to the huge amount of natural food, the chances of fish growing rapidly are enormous. However, I do, that the young generation of carps in this lake, will not grow up to mass in the future 25-40 kg, as the carp previously living in Cassien did. Often caught record specimens also stop growing, because they are under too much stress.
If the carp avoids places with a lot of food (not necessarily groundbait) just because, that the anglers sitting on the shore are disturbing him, if he has to carefully check every bite, before deciding to swallow it, how it could continue to grow? The most important factor determining the achieved sizes – but I adhere to the stubbornness of a maniac – are the genetic assumptions of the fish. The carp genotype predisposes them to reach large sizes, living in a lake with an average amount of food, will eventually be much larger than a carp with less favorable genetic makeup, but living in a very fertile lake. Numerous scientific studies prove this.
Large French carp
The large fish now living in many European waters very often come from France. They are not disturbed by other climatic conditions and are growing really fast. An example is one private lake in Denmark. The large carp population that lives there consists mainly of fish weighing from 10 do 20 kg, the average weight of carp caught was the most recent 12,5 kg. There is almost no water vegetation in the lake, there is also little natural food. The fish introduced there with a French pedigree still grow to a magnificent size.
Another example, that favorable genetic assumptions dictate the size of the fish more than, say, the temperature of the water. Provided, however, that all four of the aforementioned factors are met in a given body of water. My Dutch colleague. Leon Hoogendijk used to go fishing in a large lake in the north of France. At the same time, I was fishing in a similar size, almost identical in terms of the amount of natural food, lake in Sweden, that is, in a body of water thousands of kilometers further north. Leon, together with his colleague Leo, have caught a number of carp weighing over 15 kg. They also passed several pieces weighing over 25 kg. The average weight of all carp caught was 15 kg.
My colleagues and I also caught a lot of carp in a Swedish lake 15 kg, several pieces by weight 17,5 kg and four specimens weighing over 20 kg – one 20 kg mirror, one 20.5 kg whole-scaled carp, one mirror with a mass 21 kg and one more, 22-kilogram of full-body carp.
In this lake it was possible to catch carp even weighing over 25 kg. The average weight of carp caught by us was exactly 15 kg, so the same, what in the french lake leona. It was most certainly not a coincidence. The carp introduced into Swedish waters came from Denmark, and the local fish were of French origin.
At both lakes, all four conditions determining the growth of carp were met, including little fishing pressure. The ancestors of carps from both discussed lakes were related to each other. I think, that gives me some food for thought.
The opinion is also incorrect, as if the carp living in the far north could not reproduce. In many Scandinavian lakes, In canals and rivers, effective abrasion of carps has been reported more than once (even in Norway). Nevertheless, there is still one question that bothers me – why in so many Scandinavian waters, with large carps, these fish have no offspring, although they have excellent breeding conditions there? Fishing in some lakes in northern Europe, one often gets an impression, that the large carps living there come only from the first introduction, which was done in these lakes. If it were true, some of these fish would have to have from 80 do 100 years.
Is it possible? Here's another topic for long thought.